JPH0313704A - low NOx burner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a low NOx burner of the Punsese type.

BACKGROUND ART Conventionally, as shown in FIG. 3, this type of burner has been provided with an auxiliary flame port 23 on the outside of a flame port part 22 consisting of a large number of flame ports 21, and a part of the main flame is heated by the auxiliary flame. At the same time, the upper end of the flame holding plate 24 that forms the auxiliary flame opening 23 is folded outward or inward to direct the flow of secondary air to the auxiliary flame, thereby blowing the auxiliary flame away. The aim was to prevent this. In addition, this type of burner has a primary air ratio of the main flame and auxiliary flame of 30 to 5.
It was set between 0% and other necessary air was supplied by parallel air flowing around the burner periphery as secondary air.

Problems to be Solved by the Invention However, in the above configuration, the effect is limited to strengthening the flame holding ability, and the reduction of NOx generated from the main flame is not considered.

The present invention solves these conventional problems, and by slowing combustion and lowering the flame temperature, thermal N
This reduces the generation of Ox.

In addition, the combustion speed of the auxiliary flame is increased and the auxiliary flame is prevented from lifting, and the upper end of the flame holding plate that forms the auxiliary flame opening is folded inward so that the secondary air flow directly hits the auxiliary flame and the auxiliary flame is By preventing the main flame from being blown away, a part of the main flame is heated by a stable auxiliary flame, and the lift of the main flame that occurs when the main flame is burned at a low PA is prevented. Therefore, by reducing NOx in the main flame, which accounts for most of the combustion amount, it is possible to reduce NOx in the entire flame.

Means for Solving the Problems In order to solve the above problems, the low NOx burner device of the present invention includes a mixture chamber, auxiliary flame opening decompression chambers provided on both sides of the mixture chamber, and downstream of the mixture chamber. A flame port section comprising a large number of provided flame ports, and auxiliary flame ports provided downstream of the auxiliary flame port decompression chamber on both sides of the flame port section, forming a part of the auxiliary flame port decompression chamber. The downstream part of the flame stabilizing plate is folded back toward the flame outlet side, and an air intake port is provided in the upstream part of the auxiliary flame outlet decompression chamber.

Effect The present invention uses the above-described configuration to reduce the primary air ratio of the main flame to 2.
0% or less - By setting the primary air ratio of the auxiliary flame to around 60% and burning, the main flame's low PA combustion slows down the combustion and lowers the flame temperature, reducing thermal N.
Reduces Ox generation.

In addition, the primary air ratio of the auxiliary flame is set to about 60% to increase the combustion speed of the auxiliary flame, prevent lift of the auxiliary flame, and fold the upper end of the flame holding plate that forms the auxiliary flame port inward. The secondary air flow directly hits the auxiliary flame and prevents the auxiliary flame from being blown away, allowing the stable auxiliary flame to heat a part of the main flame. This prevents flame lift. Therefore, by reducing NOx in the main flame, which accounts for most of the combustion amount, the entire flame can be reduced in NOx.

Embodiments Hereinafter, embodiments of the present invention will be explained based on the accompanying drawings.

In FIGS. 1 and 2, 1 is a burner main body, and on the upper surface of the burner main body 1 there is a burner port part 3 in which a large number of burner ports 2 are opened. The flame port 3 is formed in a mountain shape or a semi-cylindrical shape with the apex at the center, and the flame ports 2 are provided on both inclined surfaces with the apex in between. Auxiliary air mixture ports 4 are located on both sides of the burner body 1.
are provided at appropriate intervals in the longitudinal direction, and flame holding plates 6 forming auxiliary flame opening decompression chambers 5 are attached to face each side of the burner body l. The upper end of the flame holding plate 6 is bent inward to form a horizontal portion 7, and an auxiliary flame port 8 is formed between the horizontal portion 7 and the burner body 1. At the bottom of the flame stabilizing plate 6, air intake ports 9 are provided at appropriate intervals in the longitudinal direction of the burner body 1. 10 is a mixture chamber.

In the above configuration, the air-fuel mixture inside the air-fuel mixture chamber 10 is set to have a primary air ratio (PA) of 20% or less. Most of this mixture is ejected from the flame port 2, and the remaining mixture passes through the auxiliary mixture port 4 and is led to the auxiliary gas port decompression chamber 5, where it mixes with air from the air intake port 9. The mixture becomes a mixture with a secondary air ratio of about 60% and is ejected from the auxiliary flame port 8. The secondary air flows from the bottom to the top between the burner body 1 and other burner bodies installed in parallel, and part of it flows into the auxiliary flame opening decompression chamber 5 from the air intake port 9, and the other part flows into the flame-holding chamber 5. The air flows along the outer periphery of the plate 6, is supplied as secondary air to the auxiliary burner port 8 at intervals of the horizontal portion 7, and is then also used as secondary air to the burner port 2.

Therefore, the flame formed in the flame port 3 with the above configuration is as follows.
The NOX generated from the flame consists of the main flame (PA = about 20%) formed at the flame port 2 and the auxiliary flames (PA - about 60%) formed at the auxiliary flame ports 8 at both ends. Explain the principle. NOx generated from flames is generally divided into bronze (bronze) NOx and thermal NOx, and prompt NOx.
The amount of x generated depends on the fuel. Thermal NOx
is NOx produced by reaction of N2 in the air when passing through the flame reaction zone, and the amount of NOx generated is determined by the temperature of the flame reaction zone. Incidentally, when thermal NOx is burned with a flame at a low PA, the reaction becomes slow, the flame reaction zone becomes large, the temperature of the flame reaction zone decreases, and it is possible to reduce NOx.

Therefore, in the flame formed in the burner with the above configuration, the main flame, which accounts for most of the combustion amount, can be set to a low PA of about -20% of the primary air ratio, which has the effect of significantly reducing the amount of NOx generated, and the main flame The auxiliary flames installed on both sides of the main flame can heat the base of the main flame to prevent blow-off and lift of the main flame caused by setting the PA to low. By increasing the combustion rate, the chemical reaction is stabilized, and physically, by folding the upper end of the flame stabilizing plate 6 inward to provide a horizontal part 7, the flow of secondary air is This prevents the auxiliary flame from being blown away by hitting the flame directly.

Effects of the Invention As described above, the NOx burner device of the present invention provides the following effects.

(1) A burner that has an auxiliary flame port on the outside of the flame port, which is made up of a large number of flame ports, and has an air intake port at the bottom of the decompression chamber. By providing this, it is possible to perform combustion by setting the primary air ratio of the main flame to 20% or less and the primary air ratio of the auxiliary flame to around 60%, so the main flame can be burned at a low PA and the combustion can be slowed down. turned into
By lowering the flame temperature, the generation of NOx can be reduced. Therefore, reducing NOx in the main flame, which accounts for most of the combustion amount, has the effect of reducing NOx in the entire flame.

(2) Set the primary air ratio of the auxiliary flame to about 60% to increase the combustion speed of the auxiliary flame, prevent the auxiliary flame from lifting, and move the upper end of the flame holding plate that forms the auxiliary flame port inward. Since the secondary air flow directly hits the auxiliary flame and prevents the auxiliary flame from being blown away, a stable auxiliary flame can be obtained.

(3) The base of the main flame is heated by the auxiliary flame, and the main flame has a low PA.
It is possible to prevent the lift of the main flame that occurs due to combustion.

[Brief explanation of drawings]

FIG. 1 is an enlarged perspective view of a cut-out main part of a low NOx burner according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the same, and FIG. 3 is a perspective view of a cut-out main part of a conventional burner. 10...Mixture chamber, 5...Auxiliary flame port decompression chamber, 2...flame port, 3...flame port part, 8
...Auxiliary flame opening, 6...Flame holding plate, 9...
...Air intake.

Claims (1)

[Claims] a gas mixture chamber, an auxiliary flame port provided on both sides of the mixture chamber, a decompression chamber, a flame port section including a large number of flame ports provided downstream of the mixture chamber, and the auxiliary flame port provided on both sides of the gas mixture chamber. It has an auxiliary flame port provided downstream of the flame mouth decompression chamber, and the downstream part of the flame holding plate forming a part of the auxiliary flame mouth decompression chamber is folded back toward the flame mouth side, and the auxiliary flame mouth decompression chamber is A low NOx burner with an air intake in the upstream section.